[PATCH v8 08/20] multi-process: Initialize message handler in remote device

[Jagannathan Raman <jag.raman@oracle.com>]

Initializes the message handler function in the remote process. It is
called whenever there's an event pending on QIOChannel that registers
this function.

Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
---
 MAINTAINERS              |  1 +
 hw/i386/Makefile.objs    |  1 +
 hw/i386/remote-msg.c     | 64 ++++++++++++++++++++++++++++++++++++++++++++++++
 include/hw/i386/remote.h |  4 +++
 4 files changed, 70 insertions(+)
 create mode 100644 hw/i386/remote-msg.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 41fe809..40e0654 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3046,6 +3046,7 @@ F: hw/i386/remote.c
 F: include/hw/i386/remote.h
 F: io/mpqemu-link.c
 F: include/io/mpqemu-link.h
+F: hw/i386/remote-msg.c
 
 Build and test automation
 -------------------------
diff --git a/hw/i386/Makefile.objs b/hw/i386/Makefile.objs
index 5ead266..8396958 100644
--- a/hw/i386/Makefile.objs
+++ b/hw/i386/Makefile.objs
@@ -15,6 +15,7 @@ obj-$(CONFIG_VMPORT) += vmport.o
 obj-$(CONFIG_VMMOUSE) += vmmouse.o
 obj-$(CONFIG_PC) += port92.o
 obj-$(CONFIG_MPQEMU) += remote.o
+obj-$(CONFIG_MPQEMU) += remote-msg.o
 
 obj-y += kvmvapic.o
 obj-$(CONFIG_ACPI) += acpi-common.o
diff --git a/hw/i386/remote-msg.c b/hw/i386/remote-msg.c
new file mode 100644
index 0000000..4315d2c
--- /dev/null
+++ b/hw/i386/remote-msg.c
@@ -0,0 +1,64 @@
+/*
+ * Copyright © 2020 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL-v2, version 2 or later.
+ *
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+
+#include "hw/i386/remote.h"
+#include "io/channel.h"
+#include "io/mpqemu-link.h"
+#include "qapi/error.h"
+#include "sysemu/runstate.h"
+
+gboolean mpqemu_process_msg(QIOChannel *ioc, GIOCondition cond,
+                            gpointer opaque)
+{
+    PCIDevice *pci_dev = (PCIDevice *)opaque;
+    Error *local_err = NULL;
+    MPQemuMsg msg = { 0 };
+
+    if (cond & G_IO_HUP) {
+        qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_SHUTDOWN);
+        return FALSE;
+    }
+
+    if (cond & (G_IO_ERR | G_IO_NVAL)) {
+        error_report("Error %d while processing message from proxy \
+                   in remote process pid=%d", errno, getpid());
+        return FALSE;
+    }
+
+    mpqemu_msg_recv(&msg, ioc, &local_err);
+    if (local_err) {
+        goto exit;
+    }
+
+    if (!mpqemu_msg_valid(&msg)) {
+        error_report("Received invalid message from proxy \
+                     in remote process pid=%d", getpid());
+        return FALSE;
+    }
+
+    switch (msg.cmd) {
+    default:
+        error_setg(&local_err,
+                   "Unknown command (%d) received for device %s (pid=%d)",
+                   msg.cmd, DEVICE(pci_dev)->id, getpid());
+    }
+
+    mpqemu_msg_cleanup(&msg);
+
+exit:
+    if (local_err) {
+        error_report_err(local_err);
+        return FALSE;
+    }
+
+    return TRUE;
+}
diff --git a/include/hw/i386/remote.h b/include/hw/i386/remote.h
index 5b36b25..7f9028f 100644
--- a/include/hw/i386/remote.h
+++ b/include/hw/i386/remote.h
@@ -14,6 +14,7 @@
 #include "qom/object.h"
 #include "hw/boards.h"
 #include "hw/pci-host/remote.h"
+#include "io/channel.h"
 
 typedef struct RemoteMachineState {
     MachineState parent_obj;
@@ -25,4 +26,7 @@ typedef struct RemoteMachineState {
 #define REMOTE_MACHINE(obj) \
     OBJECT_CHECK(RemoteMachineState, (obj), TYPE_REMOTE_MACHINE)
 
+gboolean mpqemu_process_msg(QIOChannel *ioc, GIOCondition cond,
+                            gpointer opaque);
+
 #endif
-- 
1.8.3.1